18131201 has 4 divisors (see below), whose sum is σ = 19779504. Its totient is φ = 16482900.

The previous prime is 18131173. The next prime is 18131203. The reversal of 18131201 is 10213181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10213181 = 11 ⋅928471.

It is a cyclic number.

It is not a de Polignac number, because 18131201 - 2⁶ = 18131137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18131201.

It is not an unprimeable number, because it can be changed into a prime (18131203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 824135 + ... + 824156.

It is an arithmetic number, because the mean of its divisors is an integer number (4944876).

Almost surely, 2^18131201 is an apocalyptic number.

18131201 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18131201 is a deficient number, since it is larger than the sum of its proper divisors (1648303).

18131201 is a wasteful number, since it uses less digits than its factorization.

18131201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648302.

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 18131201 is about 4258.0747997188. The cubic root of 18131201 is about 262.7093465294.

Adding to 18131201 its reverse (10213181), we get a palindrome (28344382).

The spelling of 18131201 in words is "eighteen million, one hundred thirty-one thousand, two hundred one".